We have a number of Macs all printing to a Windows print printer and Papercut. This has been in place for years and generally works really well. However last week we have started having issues with a few 10.6 clients where it wont authenticate as the user.

If you put in the network admin username/password it hits the print cue just fine, but if you authenticate as the user logged on then it says the username/password is incorrect. However it only says this in the console logs, and the print job just disappears.

Any ideas as to why this has just started happening and how to fix it?